Preheat oven to 450 degrees F.
In a food processor, combine the cheese, bread, onion, garlic, parsley, egg, and sauce. Blend for 30 seconds, scraping the sides as needed.
In a large bowl, combine ground beef, oregano, salt and pepper.
Add the cheese/breadcrumb/sauce mixture and gently but thoroughly combine.
Using a small ice cream scoop, measure out the meatballs and roll gently in hands to shape into a ball. Place onto prepared sheet pan. Drizzle tops lightly with oil.
Bake for 15-20 minutes, or until browned and just cooked through.
Serve with or without additional sauce.